PO102 PO704 PO702 CODES Mystery

[Steven Caudle]

My 2013 GMC 1500 keeps throwing codes. Lean bank 1, lean bank 2, out of range MAF sensor. Have replaced both O2 sensors, throttle body, smoke tested and replaced MAF yesterday and codes again today after replacing it for the 4th time. What's next ECM ???

[CamGTP]

The P0102 is a circuit code, so I'd be inspecting all the wiring before going after the PCM.

 

The other two codes are for circuits as well.

[richard wysong]

agreed , check for 5v and ground voltage drop at the maf before firing the parts cannon. I've said many times here that codes don't mean the parts bad just thats where to start your diagnosing. if those check out go to the ecm and check the resistance between the maf signal wire and the ecm. you will need a diagram of the ecm pinout

[richard wysong]

the maf may use 12v as well as the way it works is it monitors the temp of the resistor and calculates the air flow by that temp so ANY leak between the maf and the throttle will throw it off. check the crankcase vent hose and anything else connected to that hose. fix that code first and the others may not reset

[richard wysong]

make sure the pcv system is functioning properly as well. stock intake system? no K&N or cold air foolishness? clean air filter?

[dna9656]

I have a K & N filter on my 06 5.3 Avalanche, I have a whistle when getting on the freeway other than that it works fine. It was there when I bought the truck; it's being there sure makes getting to things A LOT easier than that boat anchor GM had in there; anyway I digress... Cold air intake is foolishness for sure!

The only thing I can add to the astute answers already given is this: When crazy electrical things happen on a vehicle don't neglect to check the grounds, I start there because they are usually easy to check and it just might be the cause of all the issues; not to say bad grounds are the only answer here but certainly could be a contributor.

[redvett]

PCM's rarely go bad unless you jump start a vehicle and cross the cables. Pick the P0102 and start there its the best way to work through the problem and if you haven't already go to Alldata for the diagnostic tree to find the problem.